The present invention relates to a clamp for an elongated member such as a pipe, which comprises a receiving portion defining a chamber for receiving and holding the elongated member therein, and a resilient retaining wing extending obliquely from an inlet toward a bottom of the receiving portion.
A clamp for an elongated member such as a pipe has been well-known which comprises a receiving portion defining a chamber for receiving and holding the elongated member therein, and a resilient retaining wing extending obliquely from an inlet toward a bottom of the receiving portion, wherein the resilient retaining wing has flexibility to be bendingly displaced closer to a side wall of the receiving portion when the elongated member is pressed into the receiving portion, and then engaged with an outer peripheral surface of the elongated member received in the receiving portion, so as to produce a resistance against pull-out of the elongated member from the receiving portion.
FIG. 1 shows a receiving portion of a typical clamp for an elongated member 3 such as a pipe. The receiving portion 1 defining a chamber for receiving and holding an elongated member therein is formed with a pair of resilient retaining wings 2 each extending obliquely from an inlet toward a bottom of the receiving portion. Each of the resilient retaining wings 2 has flexibility to be bendingly displaced closer to a side wall 5 of the receiving portion 1 when the elongated member 3 is pressed into the receiving portion 1. Immediately after the elongated member 3 is received in the receiving portion 1, each of the resilient retaining wings 2 will return to its original posture in such a manner that a distal end 6 thereof is engaged with an outer peripheral surface of the elongated member 3 to produce a resistance against pull-out of the elongated member 3 from the receiving portion.
Each of the resilient retaining wings 2 has one end connected to an inlet of the receiving portion 1, and can be displaced closer to a side wall 5 bendingly about the connection end serving as a support point, in its entirety. As shown in FIG. 1, when the elongated member 3 is pressed into the receiving portion 1, the elongated member 3 applies a pressing force to the resilient retaining wings 2 to cause bending thereof. In the typical clamp illustrated in FIG. 1, a distance “a” between a point 7 of application of a pressing force to the resilient retaining wing 2, and a point 8 of action of the pressing force causing the bending displacement about the support point is very short as illustrated. Thus, an insertion force for the elongated member becomes larger to cause an increase in workload on an operator in charge of insertion of a pipe or the like. If the resilient retaining wing is formed to have a lower strength so as to reduce the insertion force, the resistance against pull-out of the elongated member retained thereby will be deteriorated. Therefore, in a clamp for an elongated member such as a pipe, there is the need for reducing an insertion force of the elongated member to a receiving portion and increasing a pull-out resistance after insertion.
The following Patent Documents 1 to 5 disclose various types of elongated-member clamps:                [Patent Document 1] Japanese Patent Laid-Open publication No. 2001-099357        [Patent Document 2] Japanese Patent Laid-Open publication No. 2004-044698        [Patent Document 3] Japanese Patent Laid-Open publication No. 2005-133783        [Patent Document 4] Japanese Patent Laid-Open publication No. 2005-240837        [Patent Document 5] Japanese U. M. Laid-Open publication No. 64-027512        
Each of the elongated-member clamps disclosed in the Patent Documents 1 to 4 comprises a receiving portion, and a resilient retaining wing extending obliquely from an inlet toward a bottom of the receiving portion, wherein the resilient retaining wing has flexibility to be bendingly displaced closer to a side wall of the receiving portion when the elongated member is pressed into the receiving portion, and then engaged with an outer peripheral surface of the elongated member received in the receiving portion so as to produce a resistance against pull-out of the elongated member from the receiving portion. More specifically, in the clamp disclosed in the Patent Document 1, with a view to allowing plural types of pipes different in diameter to be received and held in a receiving portion, the receiving portion is provided with a pair of resilient retaining wings, a pair of resilient horizontal wings disposed on the side of a bottom of the receiving portion in parallel relation to the bottom, and a pair of clamping segments disposed in longitudinally parallel relation to a combination of the resilient retaining wings and the resilient horizontal wings. In the clamp disclosed in the Patent Document 2, with a view to reducing an insertion force for a pipe or the like and sufficiently ensuring a length of a resilient retaining wing, the resilient retaining wing has a connection end connected to an inlet of a receiving portion and formed with a void of a predetermined length. In the clamp disclosed in the Patent Document 3, a receiving portion is formed with a pair of first resilient retaining wings, and a pair of second resilient retaining wings extending from respective ones of intermediate positions of the first resilient retaining wings, toward a bottom of the receiving portion and beyond a distal end of the first resilient retaining wing, so as to reduce an insertion force while ensuring a resistance against pull-out of a pipe or the like. In the clamp disclosed in the Patent Document 4, with a view to allowing plural types of pipes different in diameter to be received and held in a receiving portion, the receiving portion is provided with two pairs of first resilient retaining wings, a pair of second resilient retaining wings each disposed between a corresponding one of the pairs of first resilient retaining wings to extend closer to a bottom of the receiving portion than the pair of first resilient retaining wings, and a pair of third resilient retaining wings disposed on the side of the bottom.
The clamp disclosed in the Patent Document 5 is a type devoid of a resilient retaining wing extending from an inlet of a receiving portion, wherein each of two outer ones of three end walls defining two receiving portions has flexibility, and each of the receiving portions has a bottom formed with a resilient tubular portion, so that, even if a pipe or the like varies in outer diameter thereof, the clamp can resiliently hold the pipe after insertion, while absorbing the variation.
Although each of the clamps disclosed in the Patent Documents 1 to 4 has a resilient retaining wing adapted to retain an elongated member such as a pipe received in the receiving portion so as to produce a resistance against pull-out of the elongated member, there remains the need for improvement in that each of the clamps involves some complexity in configuration. Even in the clamp disclosed in the Patent Document 2 which has a relatively simpler structure than the clamps disclosed in the Patent Documents 1, 3, and 4, it is necessary to form a void of a predetermined length in the connection end at the inlet of the receiving portion. Moreover, the formation of the void is likely to lower the strength of the resilient retaining wing and thereby deteriorate the resistance against pull-out of a pipe or the like held in the receiving portion. The clamp disclosed in the Patent Document 5 has no resilient retaining wing and thereby it is difficult to achieve high pull-out resistance.